Data from ESA’s Gaia spacecraft indicate a large galaxy collided with the Milky Way about 10 billion years ago, leaving identifiable stars strewn in its wake to help astronomers piece together our galaxy’s history.

Using data from ESA’s Gaia and Hipparcos satellites, astronomers have managed to deduce the mass of a giant exoplanet orbiting Beta Pictoris by studying subtle changes in the star’s motion over a quarter of a century.

The Hubble constant indicates how fast the Universe is expanding in the wake of the Big Bang. New observations using two independent techniques have come up with different values, signs of possible problems with current theory.

A head-on collision between the Milky Way and a smaller body dubbed the “Sausage” galaxy eight to 10 billion years ago had a profound effect on the structure and evolution of Earth’s home in space, astronomers say.

The European Space Agency’s Gaia spacecraft collected proper motion data for several million stars in the Large Magellanic Cloud, a satellite galaxy to the Milky Way, allowing astronomers to visualize its rotation in a unique fingerprint-like pattern.

The second data release from the European Space Agency’s hard-working Gaia spacecraft reveals the position and brightness of nearly 1.7 billion stars in the most detailed star catalogue ever developed.

Astronomers have created the first large-scale map that shows stellar ages in the Milky Way by determining the ages of nearly 100,000 red giant stars, at distances of up to 50,000 light-years from the galactic centre. Notably, the map confirms that our home galaxy has grown inside out: in the present epoch, most old stars can be found in the middle, more recently formed ones in the outskirts.

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